1.7 Indicate whether each of the following statements typifies descriptive statistics (because it describes sets of actual observations) or inferential statistics (because it generalizes beyond sets of actual observations). (a) On the basis of a survey conducted by the Bureau of Labor Statistics, it is estimated that 5.1 percent of the entire workforce was unemployed during the last month. (b) During a recent semester, the ages of students at my college ranged from 16 to 75 years. (c) Research suggests that an aspirin every other day reduces the chance of heart attacks (by almost 50 percent) in middle-age men. (d) Joe's GPA has hovered near 3.5 throughout college. (e) There is some evidence that any form of frustration-whether physical, social, economic, or political-always leads to some form of aggression by the frustrated person. INTRODUCTION (f) According to tests conducted by the Environmental Protection Agency, the 2018 Toyota Prius should average approximately 52 miles per gallon for combined city/ highway travel. (g) On average, Babe Ruth hit 32 homeruns during each season of his major league baseball career. (h) Research on learning suggests that active rehearsal increases the retention of newly read material; therefore, immediately after reading a chapter in this book, you should close the book and try to organize the new material. (1) Children with no siblings tend to be more adult-oriented than children with one or more siblings. 1.8 Indicate whether each of the following studies is an experiment or an observational study. If it is an experiment, identify the independent variable and note any possible confounding variables. (a) A psychologist uses chimpanzees to test the notion that more crowded living con- ditions trigger aggressive behavior. Chimps are placed, according to an impartial assignment rule, in cages with either one, several, or many other chimps. Subse- quently, during a standard observation period, each chimp is assigned a score based on its aggressive behavior toward a chimplike stuffed doll. (b) An investigator wishes to test whether, when compared with recognized scientists, recognized artists tend to be born under different astrological signs. (c) To determine whether there is a relationship between the sexual codes of primitive tribes and their behavior toward neighboring tribes, an anthropologist consults avail- able records, classifying each tribe on the basis of its sexual codes (permissive or repressive) and its behavior toward neighboring tribes (friendly or hostile). (d) In a study of group problem solving, an investigator assigns college students to groups of two, three, or four students and measures the amount of time required by each group to solve a complex puzzle. (e) A school psychologist wishes to determine whether reading comprehension scores are related to the number of months of formal education, as reported on school